Improvement in steam slide-valves



UNITED STATES PATENT OFFICE.

B. W. HUDSON, OF ALLENTOWN, PENNSYLVANIA.

IMPROVEMENT IN STEAM SLIDE-VALVES.

Specification forming part of Letters Patent No. 71,618, dated December3, 1867.

To all whom it may concern:

Be it known that I, Barca W. HUDSON, ot' Allentown, in the county ofLehigh and State of Pennsylvania, have invented certain new and usefulImprovements in Valves for Steam- Engines; and I do hereby declare thefollowing to be a full, clear, and exact description of the same,sutlicient to enable others skilled in the art to which my inventionappertains to make and use the same, reference being had to theaccompanying drawings, which are made part of this specification. y

This is an im provementin that class of steam engine valves Whose motionbeing mainly derived from the steam itself, great simplicity of parts,vfreedom of action, and promptness are secured; and my inventionconsists in a peculiar arrangement of the valve with duplicatedpassages, which it is believed secures the automatic stroke of the valvemore ei'ectually and with much greater promptness and certainty thanheretofore.

In4 the drawings, Figure l is a horizontal section at line of a valveand steam-chest embodying my improvement; Fig. 2 is a vertical sectionthereof at line y y.' Fig. 3 shows my invention applied to a valveadapted to move in a circular path. Fig. 4 is a diagram to illustratethe momentary action of the live steam operating to take the valve fromthe tappet and forward it for the action of the exhaust-steam. Fig. 5 isa diagram of the valve at one extremity of its stroke.

The same letters refer to like or corresponding parts throughout.

A represents a portion of the supply and exhaust passages of a customaryreciprocating engine, the part included between l and 2 representing theport-face, of usual construction.

B is the steam-chest, and G and D are the n steam supply and exhaustpassages, of any suitable form.

E E are two customary side ports or passages to the respective ends ofthe cylinder.

F is asomewhat capacious cavity, forming the exhaust-port andcommunicating with the exhaust-passage D.

My valve consists of a rectangular box, G, r'separated into two equalparts, H H', by an oblique or diagonal partition, I. J is a projectionfrom the lower part of the valve, which plays to and fro in theexhaust-port F, for a purpose that will hereinafter appear. Therespective extremities of the cylinder communicate alternately with theexhaust by means of the valve-passages K K', which, commencing the fullwidth of the box Gr, pass each other in opposite directions and onopposite sides of the partition I and empty into the exhaust-port onopposite sides of the projections J. In order to preserve a uniform areathroughout the length of each passage K K', the height thereof isincreased toward the discharging end in proportion to the diminishedWidth incident to the Obliquity of the partition I.

The plates 6 7 are made a little smaller than the ports E E', for apurpose that will presently appear.

The operation is as follows: rIhe piston, as it approaches the end ofits stroke in direction of black arrow, impels, by means of customaryconnection with its rod, a tappet upon the valve-rod L and shifts thevalve to the position shown in Fig. 4, so as to enable the live steamfrom the chest to flash around the portion 6 and into the fart-her side,4, of the exhaust-port F, whereit acts to project the valve to theposition shown in Fig. 2, in which-position the steam from the now fullend of the cylinder, rushing into the said farther side, 4. of theexhaust-port7 completes the stroke ofthe valve (see diagram, Fig. 5) andacts to throw entirely open the (for the time being) exhaustport E andsteam-port E', so as to reverse the piston and drive it to the otherend, Where, the valve-tappet being struck in the opposite direction, acorresponding action takes place through the other passage in the valveand its allied ports in and through the seat.

Among the many decided advantages of the above arrangement l will citethe following: The provision in the valve of two exhaustpassagesseparated by an oblique partition enables the engineer to secure anydesired lead or lap without any interference with the other end. Theavailing of the momentary force of the live steam (see diagram 4)secures an automatic advance of the valve until the steam from theexhaust end can become effective and removes the possibility of anylodgrnent or uncertain action of the valve, especially with a lightpressure and slow movement, such as are sometimes employed when itismerely desired to maintain a proper warmth in the passages, or in a slowmotion of a steam-pump where a heavy body of Water is being lifted,

for example. The provision of the ported projection I from the bottom ofthe valve, in combination with the Wide exhaust-port and their describedaccessories, affords a simple and eficient means for the automatic throwof the valve with far greater promptness and delicacy than is believedpossible with any socalled positive motion obtained by direct connectionof eccentrics or other ordinary mechanical appliances.

4I have spoken of the partition in the valve as being oblique ordiagonal and have shown it of that shape; but the partition may loe in aplane at the mid-Width of the valve.

It is designed that the valve-chest shall be placed beneath thecylinder, and thus allwater of' condensation in the cylinder andpassages will nd its Way out at the exhaustport.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is f l. The valve G, having theexhaust-passages K K, leading in reverse directions and on oppositesides of an oblique partition, I, and discharging through the projectionJ into the exhaust-port F, substantially as and for the purposes setforth.

2. The construction of the ends 6 and 7 of the valve in relation to theside ports, E and E', to permit steam from the chest to ash around themand through the valve, substantially as and for the purposes set forth.A

To the above specification of my improvement in valves for steam-enginesI have set my hand this 24th day ot' April, 1867.

B. W. HUDSON.

Witnesses:

J AMES L. EWIN, OoTAVIUs KNIGHT.

